This coming Saturday, if it is clear, well placed New Yorkers can go outside at sunset and watch their city act like a modern version of Stonehenge. Manhattan's streets will flood dramatically with sunlight just as the Sun sets precisely at each street's western end. Usually, the tall buildings that line the gridded streets of New York City's tallest borough will hide the setting Sun. This effect makes Manhattan a type of modern Stonehenge, although only aligned to about 30 degrees east of north. Were Manhattan's road grid perfectly aligned to east and west, today's effect would occur on the Vernal and Autumnal Equinox, March 21 and September 21, the only two days that the Sun rises and sets due east and west. Pictured above in this horizontally stretched image, the Sun sets down 34th Street as viewed from Park Avenue. If Saturday's sunset is hidden by clouds do not despair -- the same thing happens twice each year: in late May and mid July. On none of these occasions, however, should you ever look directly at the Sun.

The spiral arms of bright, active galaxy M106 sprawl through this remarkable multiwavelength portrait, composed of image data from radio to X-rays, across the electromagnetic spectrum. Also known as NGC 4258, M106 can be found toward the northern constellation Canes Venatici. The well-measured distance to M106 is 23.5 million light-years, making this cosmic scene about 60,000 light-years across. Typical in grand spiral galaxies, dark dust lanes, youthful star clusters, and star forming regions trace spiral arms that converge on a bright nucleus. But this composite highlights two anomalous arms in radio (purple) and X-ray (blue) that seem to arise in the central region of M106, evidence of energetic jets of material blasting into the galaxy's disk. The jets are likely powered by matter falling into a massive central black hole.

In this alluring time exposure, star trails arc across the night sky above foggy Monterey Bay and the lights of Santa Cruz, California in the United States of America. Since the exposure began around 2:56am PDT on July 2 it also records the trail of a Delta II rocket lofting NASA's OCO-2 spacecraft into orbit. Seen from a vantage point 200 miles north of the Vandenberg Air Force Base launch site, the trail represents the first five minutes of the rocket's flight along a trajectory south and west over the Pacific to join the A-Train in polar orbit around planet Earth. The entire trail through main engine cut-off is captured, with a very faint puff at the end marking the nose fairing separation. Under the rocket's path, the two brightest trails are the alpha and beta stars of the constellation Grus, flying high in southern skies. The OCO-2 mission goal is a study of atmospheric carbon dioxide, watching from space as planet Earth breathes.

The prominent ridge of emission featured in this vivid skyscape is known as the Cygnus Wall. Part of a larger emission nebula with a distinctive shape popularly called The North America Nebula, the ridge spans about 10 light-years along an outline that suggests the western coast of Mexico. Constructed from narrowband image data, the cosmic close-up maps emission from sulfur, hydrogen, and oxygen atoms to red, green, and blue colors. The result highlights the bright ionization front with fine details of dark, dusty forms in silhouette. Sculpted by energetic radiation from the region's young, hot, massive stars, the dark shapes inhabiting the view are clouds of cool gas and dust with stars likely forming within. The North America Nebula itself, NGC 7000, is about 1,500 light-years away. To find it, look northeast of bright star Deneb in the high flying constellation Cygnus.

Spiral galaxy NGC 4651 is a mere 62 million light-years distant, toward the well-groomed northern constellation Coma Berenices. About the size of our Milky Way, this island universe is seen to have a faint umbrella-shaped structure that seems to extend (left) some 100 thousand light-years beyond the bright galactic disk. The giant cosmic umbrella is now known to be composed of tidal star streams - extensive trails of stars gravitationally stripped from a smaller satellite galaxy. The small galaxy was eventually torn apart in repeated encounters as it swept back and forth on eccentric orbits through NGC 4651. In fact, the picture insert zooms in on the smaller galaxy's remnant core, identified in an extensive exploration of the system, using data from the large Subaru and Keck telescopes on Mauna Kea. Work begun by a remarkable collaboration of amateur and professional astronomers to image faint structures around bright galaxies suggests that even in nearby galaxies, tidal star streams are common markers of such galactic mergers. The result is explained by models of galaxy formation that also apply to our own Milky Way.

What's happened to the center of this galaxy? Unusual and dramatic dust lanes run across the center of elliptical galaxy Centaurus A. These dust lanes are so thick they almost completely obscure the galaxy's center in visible light. This is particularly unusual as Cen A's red stars and round shape are characteristic of a giant elliptical galaxy, a galaxy type usually low in dark dust. Cen A, also known as NGC 5128, is also unusual compared to an average elliptical galaxy because it contains a higher proportion of young blue stars and is a very strong source of radio emission. Evidence indicates that Cen A is likely the result of the collision of two normal galaxies. During the collision, many young stars were formed, but details of the creation of Cen A's unusual dust belts are still being researched. Cen A lies only 13 million light years away, making it the closest active galaxy. Cen A, pictured above, spans 60,000 light years and can be seen with binoculars toward the constellation of Centaurus.

To see a vista like this takes patience, hiking, and a camera. Patience was needed in searching out just the right place and waiting for just the right time. A short hike was needed to reach this rugged perch above a secluded cove in Julia Pfeiffer Burns State Park in California, USA. And a camera was needed for the long exposure required to bring out the faint light from stars and nebulae in the background Milky Way galaxy. Moonlight illuminated the hidden beach and inlet behind nearby trees in the above composite image taken last month. Usually obscured McWay Falls is visible just below the image center, while the Pacific Ocean is in view to its right. The above image is a high-resolution sequel to a similar image that appeared last year.

Orion's belt runs just along the horizon, seen through Earth's atmosphere and rising in this starry snapshot from low Earth orbit on board the International Space Station. The belt stars, Alnitak, Alnilam, and Mintaka run right to left and Orion's sword, home to the great Orion Nebula, hangs above his belt, an orientation unfamiliar to denizens of the planet's northern hemisphere. That puts bright star Rigel, at the foot of Orion, still higher above Orion's belt. Of course the brightest celestial beacon in the frame is Sirius, alpha star of the constellation Canis Major. The station's Destiny Laboratory module is in the foreground at the top right.

June 24th marked the first full Martian year of the Curiosity Rover's exploration of the surface of the Red Planet. That's 687 Earth days or 669 sols since its landing on August 5, 2012. To celebrate, consider this self-portrait of the car-sized robot posing next to a rocky outcrop dubbed Windjana, its recent drilling and sampling site. The mosaicked selfie was constructed with frames taken this April and May using the rover's Mars Hand Lens Imager (MAHLI), intended for close-up work and mounted at the end of the rover's robotic arm. The MAHLI frames used exclude sections that show the arm itself and so MAHLI and the robotic arm are not seen. Famous for panoramic views, the rover's Mastcam is visible though, on top of the tall mast staring toward the left and down at the drill hole.

Early morning risers were treated to a beautiful conjunction of Venus and waning Crescent Moon on June 24, captured in this seaside photo near Belmar, New Jersey, USA, planet Earth. The serene celestial pairing is seen above the Atlantic Ocean horizon as the eastern sky grows brighter with dawn's early light. Wispy, scattered clouds appear in silhouette. But the exposure also reveals the night side of the lunar orb in the arms of the sunlit crescent. That shadowed part of the Moon, with hints of the smooth, dark lunar seas or maria, is illuminated by Earthshine, sunlight reflected from planet Earth itself.

These are galaxies of the Hercules Cluster, an archipelago of island universes a mere 500 million light-years away. Also known as Abell 2151, this cluster is loaded with gas and dust rich, star-forming spiral galaxies but has relatively few elliptical galaxies, which lack gas and dust and the associated newborn stars. The colors in this remarkably deep composite image clearly show the star forming galaxies with a blue tint and galaxies with older stellar populations with a yellowish cast. The sharp picture spans about 3/4 degree across the cluster center, corresponding to over 6 million light-years at the cluster's estimated distance. Diffraction spikes around brighter foreground stars in our own Milky Way galaxy are produced by the imaging telescope's mirror support vanes. In the cosmic vista many galaxies seem to be colliding or merging while others seem distorted - clear evidence that cluster galaxies commonly interact. In fact, the Hercules Cluster itself may be seen as the result of ongoing mergers of smaller galaxy clusters and is thought to be similar to young galaxy clusters in the much more distant, early Universe.

What flowers in this field of dark star dust? The Iris Nebula. The striking blue color of the Iris Nebula is created by light from the bright star SAO 19158 reflecting off of a dense patch of normally dark dust. Not only is the star itself mostly blue, but blue light from the star is preferentially reflected by the dust -- the same affect that makes Earth's sky blue. The brown tint of the pervasive dust comes partly from photoluminescence -- dust converting ultraviolet radiation to red light. Cataloged as NGC 7023, the Iris Nebula is studied frequently because of the unusual prevalence there of Polycyclic Aromatic Hydrocarbons (PAHs), complex molecules that are also released on Earth during the incomplete combustion of wood fires. The bright blue portion of the Iris Nebula spans about six light years. The Iris Nebula, pictured above, lies about 1300 light years distant and can be found with a small telescope toward the constellation of Cepheus.